574 



try and the low regions,, or geologic basins. 

 Even where the real chains of mountains rise like 

 rocky dykes issuing from a crevice, counter- 

 forts that are more or less considerable, seem 

 to indicate their lateral heaving-up. While I 

 recognize the difficulty of well circumscribing 

 the groupes of mountains and the basins or 

 continued plains, I have attempted to calcu- 

 late their surfaces according to the statements 

 contained in the preceding sheets. 



SOUTH AMERICA. 

 I. Mountainous part : 



Square 

 Marine Leagues * 



Andes 58,900 



Chain of the shore of Venezuela 1,900 



Sierra Nevada de Merida 200 



Groupe of Parime 25,800 



System of the mountains of Brazil 27,600 



114,400 



II. Plains : 



Llanos of Lower Oroonoko, Meta and 



Guaviare 29,000 



Plains of the Amazon 260,400 



Pampas of Rio de la Plata, and Patagonia 135,200 

 Plains between the eastern chain of the 



Andes of Cundinamarca and the chain 



ofChoco 12,300 



Plains of the shore, on the west of the 



Andes 20,000 



456,900 



